Electric inductor relay



Feb. 6, 1940. E, WELLS 2,189,597

ELECTRIC INDUCTOR RELAY Filed Nov. 6, 1937 Fig,

WITNESSES: INVENTOR I id WK.- BY

L ancelotf. WeZZs.

Patented Feb. 6, 1940 2,189,597 ELECTRIC mnooroa RELAY Lancelot ErnestWells, Northampton, England, assignor to The Express Lift CompanyLimited,

Westminster, London, England, a

Application November 6, 1937, Serial No.

British com- In Great Britain November 26, 1933 6 Claims.

My invention relates to electric relays, and more particularly toinductor relays of the kind which are operated by relative movement be-,tween a relay body, having-relay contacts, and a plate of magnetizablematerial. Such relays are, as is known, commonly used in electricallyoperated elevator systems and also in train control systems.

One object of my invention is to provide an inductor relay in which thecontact members will open and close positively and rapidly in responseto the passage of a magnetizablc plate ad- J'acent thereto orsuccessively in response to the passage of a plurality of platesfollowing each other at high speed.

Another object is to provide an inductor relay which shall not beaffected by mechanical shocks or by magnetic interference by reason ofironwork in an elevator shaftway, or by other ad- 20 J'acent inductorplates.

It is also an object of the invention to provide an inductor relay whichshall be simple in construction, economical to manufacture and maintainin operation and which shall require a mini- 25 mum amount ofadjustment.

According to the present invention in a relay, an armature associatedwith relay contacts is arranged to be attracted against a biasing forceto collector pole pieces by magnetic flux from a 30 magnet, and acooperating magnetizable means is adapted, on movement relative to saidpole pieces, to short circuit the said flux path from the said magnet tothe pole pieces and thus effect release of the said armature and hencechange the state of the contacts associated with the armature.

Also, in' this relay, the collector poles may be spaced apart from thepoles, with the magnetizable means disposed to move relatively to the 40pole pieces and in the space between the magnet and the pole pieces toshort circuit the flux from the magnet, and the armature may be arrangedto be attracted to one of the collector pole pieces and to form a partof the magnetic circuit between the collector pole pieces.

For a better understanding of the invention, reference may be had to theaccompanying drawing, in which:

Figure 1 is a plan view of an inductor relay constructed in accordancewith my invention for use in an elevator system; and,

Fig. 2 is a view, in front elevation, of the relay illustrated in Fig.1.

Referring more particularly to the drawing, I have illustrated aninductor relay comprising a main magnet I of horseshoe shape, a pair ofcooperating collector pole pieces 2 and 3 and an armature 4. The magnetI may be energized in any desired manner, but is preferably what isknown as a magnet of high magnetic rema- 5 nence usually known as apermanent magnet and is shown as mounted upon an outer extension 5 of abase 6. The base 6 is preferably a casting of non-magnetizable materialwhich is mounted upon a suitable bracket or support 1, 10 a rubberwasher 8 being disposed between the base and the bracket to cushion therelay and the base upon the bracket.

The collector pole pieces -2 and 3 are preferably of soft iron of lowmagnetic remanence and are separated from the magnet I by an air gap 9and are mounted upon another extension II on the base 6. The pole pieces2 and 3 are supported in position by fastening them to a brass plate l2which is secured to the extension H by a pair of screws l3 and I4, eachscrew being provided with a rubber bushing I5 where it passes throughthe brass plate to insulate and deaden the noise of operation of therelay. A rubber mat or plate I6 is also disposed between the brass platei 2 and the base extension H to provide a noiseless mounting for theactive parts of the relay. The armature 4 is mounted upon the knife-edgeportion H of a magnetizable member l8, which is mounted upon thecollector pole piece 2, as by welding l9, or in any other suitablemanner.

A screw 2| is passed through the armature 4 and screwed into theknife-edge end of the magnetizable member pole extension l8, and awasher 22, is mounted upon the screw 2| to press against the armature 4and hold it against the knife-edge l1 so that it will be free to rockupon the knife-edge and thus move its arm 24 into and out of operatingposition with the pole piece 3. A rubber washer 23 is disposed onthe-screw 2| in position between the washer 22 and the armature. Aspring 25 is mounted upon the screw 2| to bias the metal washer 22 andthe rubber washer 23 toward the armature 4 so as to hold it lightly andresiliently in its operative position without permitting it to becomenoisy on its axis when it is being attracted or being released by thepole pieces.

One end 30 of the armature 4 extends along the pole extension l8 and isprovided with a pin 3| disposed to extend outwardly into engagement witha spring 32, upon the free end of which is mounted a contact member 33.The contact member 33 is disposed to cooperate with a conblock ll of anydesired shape,

tact member 34 mounted upon the free end of a resilient spring 35. Thesprings 32' and 35 are firmly mounted in a mounting block 36 and are proided with conductor extensions 39 and 38 by me us of which the relay maybe connected in the electrical circuit to be controlled. A buffer isprovided for limiting the movement of the spring members 32 and 35. Asis shown, the spring member 32, by exerting pressure against the pin 3|on the arm 30, biases the other arm 24 of the armature away from thepole piece 3; When the pole piece 3 is energized, it attracts thearmature arm 24 against the biasing force of the spring 32 and thusopens the contact members 33 and 34. When the pole piece 3 isdeenergized, the spring 32 is released from the force exerted against itand thus clos the contact members.

In order to further decrease the operation noise of the relay, a thinsheet of non-magnetizable material 43, preferably of a resilientshock-absorbing nature, is mounted upon the upper face of the pole piece3 at the point where the armature arm 24 is attracted to the pole piecewhen the pole piece is energized.- This sheet 43 should be thin enoughto provide for good operation between the pole piece and the armature,but of sufficient shock-absorbing qualities as to not only prevent thearmature from coming into physical contact with the pole piece, but todeaden the noise which might otherwise be occasioned by the operation ofthe armature. A sheet of shock-absorbing material 44 is also mountedupon pole extension member l8 where the armature arm 3|) engages it whenthe pole pieces and armature are deenergized. This is also provided forpreventing physical contact between the members 38 and I8 for thepurpose of rendering the relay more quiet in operation,

A vane or sheet 45 of magnetizable material is provided for use as aninductor plate to be disposed in the slot 9 for the purpose of shortcircuiting the magnetic flux from the main magnet desired to deenergizethose pole pieces for the purpose of releasing the armature 4.

A small magnet 48 is mounted above the upper face of the pole piece 3for the purpose of imparting snap action to the opening movement of thearmature 24 and for assisting in the elimination of any contact bounceof the armature, especially at the moment of first contact between thecontact members .33 and 34 on the springs 32 and 35. The auxiliarymagnet 48 may be of any suitable permanent magnetic material and butpreferably a permanent horse-shoemagnet, is mounted upon and supportedby a shield plate 50 which is mounted upon the upper end of the polepiece 3 for the purpose of preventing leakage of flux from the mainmagnet directly to the armature arm 24 and also to preventdemagnetization of the pull of magnet 48. The shield 5|) is preferablyconstructed in the form of an open box or hood, of sheet iron ofreasonably high permeability or of a non-permanent magnetic alloy suchas is sold under the trade-mark Hyperni or under the term stalloy (aniron silicon alloy). The shield may be secured to the pole piece 3 inany suitable manner as by welding, extend the floor of the shield downalong the side of the pole piece 3 and secure it thereto by means ofsuitable counter-sunk screws (not shown) The magnet 48 may be mounted onthe spacing block the parts directly associated sition with referencesoldering etc., but I prefer to floor of the shield by means of anonmagnetic 48* and a screw 48.

The shield is provided for preventing the flux from the main magnet ldemagnetizing the small magnet 48. Although the shield is to some extentin the magnetic circuit of the small magnet 48, the poles of the latterare disposed so close to the armature 24 that there is very littlemagnetic leakage and whether or not the shield has any effect upon thelatter has not beenfound to be of any practical importance.

A pair of U-shaped magnetizable members 52 v and 53 are. mounted againstthe inner face of the slot 9 in the central portion of the base 8 withtheir arms extending outwardly into magnetizable engagement with themain magnet and the collector pole pieces. The member 52 extends fromthe upper part or pole 55 of the magnet I around the inner portion ofthe slot 8 and into magnetic engagement with the pole piece 3. Themember 53 extends around the inner portion of the slot 9 with its outerends disposed in magnetic engagement with the pole 58 of the magnet iand the pole piece 2. The members 52 and 53 act as flux divertersdeterminable magnetic bias on the switch unit. thus enabling spring 32to be made stronger than could otherwise be done. It then becomespossible to regulate the efiective armature movements by adjusting theposition of the small mag-' net 48 in relation to they armature, and thetension of spring 32 upon the'armature. Ifdesired, each of the fluxdiverters may have a step piece 54 placed between itself and the polepiece it serves for the purpose of reducing the air gap therebe tween.

A cover plate 51 is provided for covering the main magnet I and thatportion of the base 5 upon which it is mounted. A cover plate 58 isprovided for covering the collector pole pieces, therewith and thatportion of the base 6 upon which they are mounted. The covers 51 and 58are lined preferably with a suitable rubber or other sound deadeningcomposition 58- to reduce the operating noise of the relay and protectits various parts from dust and other deteriorating influences.

The relay may be used system in which an efficient and practicallynoiseless inductor relay is desired. However, its most desirable fieldof use is probably in connection with the operation of elevator cars intheir hatchways. In elevator systems for operating the cars in theirhatchways, it is often desirable to have an inductor relayfor operatingdoor switches, lock switches or switches for controlling thedeceleration and stopping of the car. When the present inductor relay isused in an elevator system, it will be assumed that the relay supportedupon the bracket 1 will be mounted on the elevator car (not shown) byattaching the bracket 1 to some suitable part of the car. It will alsobe assumed that the inductor plate 45 is mounted in the hatchway (notshown) in cooperative poto the relay on the car so that as the car movesup and down the hatchway the inductor plate will pass through the relayslot 9.

Assuming that manent magnet, then when the car is in such position inthe hatchway that the inductor plate 45 is not in the air gap 9, theflux from the main magnet pole pieces 55 and 56 flows across the air gap9 and energizes the collector pole pieces 2 and 3. In this condition,the armature arm 24- to provide a permanent pre- 25 in connection. withany the main magnet I is a per- 9,189,597 is attracted to the pole piece3 and is held against the plate 43. The attraction of the armature 4causes its arm 30 to move the pin 3| outwardly against the spring arm 32and thus push it away from the spring arm 35 so that the contact members33 and 34 are opened and held in their open position.

Assuming now that the car moves along its hatchway until the inductorplate 46 enters the air gap 9, then the inductor plate short circuitsthe flux from the magnet l to the pole pieces 2 and 3 and therebydeenergizes these pole pieces. The deenergization oi the collector polepieces releases the arm 24 01' the armature 4 from its attractedposition against pole piece 3. The biasing action of the spring 32against the pin 3| on the arm 30 01' the armature tilts the armature sothat its arm 24 moves away from the pole piece 3 and toward theauxiliary magnet 48. The attraction of the auxiliary magnet causes thearm 24 of the armature to move toward that magnet with a quick, snapaction, and also renders the movement of the armature positive andbouncefree.

Assuming that the car moves on past the inductor plate 46, then as theplate leaves the air gap 9, the flux from the main magnet I again flowsto the collector pole pieces 2 and 3 and energizes them to attract thearm 24 of the armature 4 into its position in magnetic engagement withthe pole piece 3. This operation of the armature causes its arm 30 tomove the pin 3| outwardly against the spring 32 and thereby separate thecontact members 33 and 34. The opening or closing of the contact membersmay be used to control a circuit as desired.

Although the contact members 33 and 34 have been illustrated as beingclosed when the inductor plate 46 is disposed in the air gap, it isobvious that the contact members may be so arranged that they will openwhen the inductor plate is in the air gap and close when it leaves theair gap.

It will also be apparent that the use of shockabsorbing andsound-deadening material as described contributes to the silent andeiiicient operation of the relay and that the construction described isin a compact form so that a plurality of relays may be grouped closelytogether in a common mounting bracket on an elevator car. It will alsobe obvious that where a plurality of these relays are provided on onecar, magnetic shielding means of suitably disposed sheets ofmagnetizable material may be provided where desirable for each unitwhereby the effect of the magnets of adjacent units upon the armaturesnot served by them will be minimized.

Although I have illustrated and described only one specific embodimentof my invention, it is to be understood that many changes therein andmodifications thereof may be made without departing from the spirit andscope of the invention.

I claim as my invention:

1. A relay comprising a pair of collector pole pieces, a permanentmagnet provided with a pair of poles disposed to energize the collectorpole pieces, means for supporting the collector pole pieces and themagnet with air gaps between the poles of the magnet and the collectorpole pieces, an armature disposed to be attracted by one of thecollector pole pieces when they are magnetized, and a magnetizable platefor movement through the air gaps between the collector pole pieces andthe poles of the magnet to short circuit the flux from the magnet,thereby deenergizing the collector pole pieces to release the armature.

2. A relay comprising a pair oi collector pole pieces, a permanentmagnet provided with a pair poles disposed to energize the collectorpole I pieces, means for supporting the collector pole pieces and themagnet with air gaps between the poles of the magnet and the collectorpole pieces, an armature disposed to be attracted by one of thecollector pole pieces when they are magnetized, a magnetizable plate formovement through the air gaps between the collector pole pieces and thepoles of the magnet to short circuit the flux from the magnet, therebydeenergizing the collector pole pieces to release the armature and IImeans for supporting the armature with its body portion providing a partof the magnetic circuit between the collector pole pieces.

3. A relay comprising a pair oi collector pole pieces, a permanentmagnet provided with a pair I of poles disposed to energize thecollector pole pieces, means for supporting the collector pole piecesand the magnet with air gaps between the poles of the magnet and thecollector pole pieces, an armature disposed to be attracted by one ofthe collector pole pieces when they are magnetized, a magnetizable platefor movement through the air gaps between the collector pole pieces andthe poles of the magnet to short circuit the flux from the magnet,thereby deenergizing the collector pole pieces to release the armature,and flux diverting strips disposed at one side of said air gaps forproviding flux paths from the magnet poles to the collector pole piecesaround one side of the air gaps to render the armature more eifective inoperation. I

4. A relay comprising a pair 01' collector pole pieces, a permanentmagnet provided with a pair of poles disposed to energize the collectorpole pieces, means for supporting the collector pole pieces and themagnet with air gaps between the poles of the magnet and the collectorpole pieces, an armature disposed to be attracted by one 01' thecollector pole pieces when they are magnetized, a magnetizable plate formovement through the air gaps between the collector pole pieces and thepoles of the magnet to short circuit the flux from the magnet, therebydeenergizing the collector pole pieces to release the armature, and apair of U-shaped flux diverters disposed around 5 said air gaps toprovide flux diverting paths from the magnet poles to the collector polepieces.

5. A relay comprising a' pair of collector pole pieces, a permanentmagnet provided with a pair of poles disposed to energize the collectorpole pieces, means for supporting the collector pole pieces and themagnet with air gaps between the poles of the magnet and the collectorpole pieces, an armature disposed to be attracted by one oi thecollector pole pieces when they are magnetized, a magnetizable plate formovement through the air gaps between the collector pole pieces and thepoles of the magnet to short circuit the flux from the magnet, therebydeenergizing the collector pole pieces to release the armature, and anauxiliary magnet disposed adjacent to the armature for assisting themovement of the armature away from the pole piece by which it isreleased.

6. A relay comprising a pair oi collector pole pieces, a permanentmagnet provided with a pair of poles disposed to energize the collectorpole pieces, means for supporting the collector pole pieces and themagnet with air gaps between the poles oi the magnet and the collectorpole pieces, 78

. 4 an disposed to be attracted by one of the collector pole pieces whenthey are magnetized, a magnetizable plate for movement through the airgaps between the collector pole pieces and the poles of the magnet toshort circuit the flux from the magnet, thereby deenergizing thecollector pole pieces to release the armature, an

auxiliary magnet disposed aidjacent to the armature for assisting tureaway from the pole piece by which it is released, and a. magnetic shielddisposed to limit leakage of flux fromthe magnet to the auxiliary 5magnet or armature.

LANCELOT' E. WELLS.

the movement of the arma-

